The invention relates to a spherical ceramsite petroleum propping agent coated with silicon resin in a bonded mode and a preparing method thereof'. The preparing technology includes the steps that under the effect of a catalyst, several kinds of organosilicon monomers and micro-spherical ceramsite are heated through different temperature stage programs and sequentially subjected to a series of reactions such as hydrolyzing, polycondensation, alkoxy-ester exchanging, polymer structure reforming and high-temperature curing, and the ceramsite propping agent coated with the silicon resin is obtained. The propping agent is smooth in surface and good in chemical stability, can be resistant to the high temperature higher than 500 DEG C, and is not chemically reacted with fracturing fluid and oil gas, and the environment and underground water are not polluted; the propping agent has excellent oleophylic and hydrophobic characteristics; the globular degree can be higher than 95%; bulk density ranges from 1.2 to 1.3, apparent density ranges from 2.20 to 2.50; intensity is high, and the crashed rate is smaller than 5% under the closure pressure of 80 Mpa; the propping agent is suitable for exploiting multiple kinds of oil-gas wells.